添加用户和Mqtt的仓储文件，添加的对Excel进行导入导出功能，并完成单元测试

Data/Repositories/UserRepository.cs

@@ -0,0 +1,75 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using PMSWPF.Data.Entities;
+
+namespace PMSWPF.Data.Repositories;
+
+/// <summary>
+/// 用户仓储类，用于操作DbUser实体
+/// </summary>
+public class UserRepository
+{
+    /// <summary>
+    /// 根据ID获取用户
+    /// </summary>
+    /// <param name="id">主键ID</param>
+    /// <returns></returns>
+    public async Task<DbUser> GetByIdAsync(int id)
+    {
+        using (var _db = DbContext.GetInstance())
+        {
+            return await _db.Queryable<DbUser>().In(id).SingleAsync();
+        }
+    }
+
+    /// <summary>
+    /// 获取所有用户
+    /// </summary>
+    /// <returns></returns>
+    public async Task<List<DbUser>> GetAllAsync()
+    {
+        using (var _db = DbContext.GetInstance())
+        {
+            return await _db.Queryable<DbUser>().ToListAsync();
+        }
+    }
+
+    /// <summary>
+    /// 新增用户
+    /// </summary>
+    /// <param name="user">用户实体</param>
+    /// <returns></returns>
+    public async Task<int> AddAsync(DbUser user)
+    {
+        using (var _db = DbContext.GetInstance())
+        {
+            return await _db.Insertable(user).ExecuteReturnIdentityAsync();
+        }
+    }
+
+    /// <summary>
+    /// 更新用户
+    /// </summary>
+    /// <param name="user">用户实体</param>
+    /// <returns></returns>
+    public async Task<int> UpdateAsync(DbUser user)
+    {
+        using (var _db = DbContext.GetInstance())
+        {
+            return await _db.Updateable(user).ExecuteCommandAsync();
+        }
+    }
+
+    /// <summary>
+    /// 根据ID删除用户
+    /// </summary>
+    /// <param name="id">主键ID</param>
+    /// <returns></returns>
+    public async Task<int> DeleteAsync(int id)
+    {
+        using (var _db = DbContext.GetInstance())
+        {
+            return await _db.Deleteable<DbUser>().In(id).ExecuteCommandAsync();
+        }
+    }
+}